Endotherm

An endotherm is an organism that maintains its body at a metabolically favorable temperature mainly through heat released by internal bodily functions, rather than relying almost entirely on ambient heat. Heat production can include shivering and uncoupled oxidative metabolism in brown adipose tissue. Birds and mammals are considered truly endothermic animal groups, while several other animals are described as mesothermic or seasonally endothermic. Endothermy is commonly called warm-bloodedness.

Definition

An organism that maintains a favorable body temperature using internal heat

True endothermic groups

Birds and mammals

Opposite process

Ectothermy